This invention relates to the field of medical suction devices, and in particular to suction wound drains.
Closed suction drains are ubiquitously used in medical practice to suction and collect fluid and other material from surgical wounds. For example, surgical wounds frequently benefit from drainage during the post operative period. This can involve removing fluid which is naturally expressed from the wounds, characterizing and measuring drained fluids, and monitoring the operative site for unexpected or undesired leakage of fluids. Hence, the drains are effective in promoting healing and recovery, while minimizing the likelihood of infection. Known closed suction wound treatment devices, such as Jackson-Pratt evacuator drain systems, typically include a small plastic semi-spherical or football-shaped bulb which supplies suction to a drainage tube that the surgeon leaves within the patient's wound. This suction bulb, which is connected to the drainage tube via a one-way Heimlich valve, also serves as a collection reservoir for fluid drained from the wound. When removing such surgical drains from the patient, one simply pulls the drain from the patient's wound.
Despite the wide use of these closed-system wound drain devices, their suction characteristics remain poorly understood. For example, one common assumption is that releasing suction within the bulb also releases suction at the drain end of the drainage tube. The present inventors have discovered through clinical observations, however, that suction is not released at the drain element after release of the bulb section, as previously thought. What is more, many current approaches do not provide a mechanism whereby an active drainage system can be efficiently converted to a passive drainage system. Again, the present inventors have discovered that passive drainage is not simply achieved by release of the bulb section.
In light of the above unexpected limitations of traditional closed-system suction wound drains, what is needed are drainage devices and methods to optimize drainage function by providing easy and safe dissipation of the negative suction prior to removing the drain from the patient. What is also needed are devices and methods that provide safe and efficient transformation from an active drainage system to a passive drainage system. What is further needed are calibrated suction bulbs for applying a controlled vacuum to a wound site. The present invention provides such solutions.